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Deep Sjeng 3.x

Deep Sjeng 3.x is the third incarnation of the Deep Sjeng engine. It
significantly improves upon the strengths of the Deep Sjeng 2.x engine,
bringing faster, deeper search, longer-range planning and an enhanced
understanding of active piece play, as well as more endgame knowledge.
The result is a cut-throat chess opponent and analysis partner with a great
understanding of dynamic compensation. Deep Sjeng 3.0 is about 100 ELO
stronger than Deep Sjeng 2.7.

Deep Sjeng WC2008 is an enhanced version of Deep Sjeng 3.0 that is the
World Computer Speed Chess Champion 2008.
It is a free upgrade for Deep Sjeng 3.x and is included with the package
for new customers.

Features

World Computer Speed Chess Champion 2008

Top strength class chess engine

Multiprocessor support (SMP, dual core, quad core, ...)

Up to 8 CPUs supported

Fully adjustable difficulty levels

Engine supports UCI 1.0 and 2.0 protocols

Compatible with almost all chess GUI and databases

Multi-variation analysis

Refutation displays

Fischerandom chess (Chess960) supported

Windows Vista compatible

New in WC2008: Nalimov endgame tablebase support

Download/Order

Frequently Asked Questions

What is the ideal hash size for blitz/bullet/long games?

Deep Sjeng uses an optimized hash table implementation that can make full use of any memory
you give it. So the answer is always: as much as possible! Of course you should not allocate
so much memory that your machine starts swapping to disk. A good guideline is to allocate
half the amount of RAM you have, or one third if you play engine-engine matches. Deep Sjeng
itself has no problems to play 1 minute games with 2Gb of hash.

Does Deep Sjeng 3.x come with an opening book?

No opening book is included for now. In general Deep Sjeng plays all openings well and works
fine with the free books you can find on the internet. However we will probably make a book
available later on which emphasises the active style of the engine. Please check back the website
regularly.

How do I enable Nalimov endgame databases?

During testing of Deep Sjeng 3.x we found that the advantage of endgame databases is often
grossly overstated and there is in reality essentially no benefit. Particularly on a loaded
machine or on a laptop they might even make chessprograms play worse! So we made the decision
to remove EGTB support from Deep Sjeng 3.x and instead implement as much endgame knowledge
as possible directly into the engine. The result is that the engine is now much stronger in the
late middlegame (where EGTB cannot help much), at the expense of very seldomly allowing a won game
to be drawn or a drawn game to be lost in the deep endings.
In Deep Sjeng WC2008 tablebase support was re-added for customers that require it for deep endgame
analysis.

Why should I buy a bare engine without a GUI?

All chessprograms are so strong nowadays that even free programs are good enough to beat all
chessplayers. However, for analyzing games it is essential to have strong engines available
with different playing styles. They can help you by suggesting alternate plans possible in a
position. Deep Sjeng is such a strong engine with a very particular playing style.
Additionally, you can configure Deep Sjeng to play at your ELO level, so you get a perfectly
matched opponent.

Do you have some examples of the playing style?

In the 8th International CSVN Tournament Deep Sjeng thrashed a strong field of engines to
take second place, just half a point behind Rybka running on much faster hardware.
You can find the games here:
ICT8 Tournament PGN

Can I use Deep Sjeng 3 with WinBoard/ICC/chessclub.com/FICS?

Yes! The Dasher interface supports Deep Sjeng in UCI mode directly for analysis and playing.
Consult the Dasher help for instructions. To play on the server, you can use WinBoard with
Polyglot.
An example Polyglot configuration file is here as well as a
book.